PCA1070T 查看數據表（PDF） - Philips Electronics
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PCA1070T Datasheet PDF : 36 Pages
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Philips Semiconductors
Multistandard programmable analog
CMOS transmission IC
Product specification
PCA1070
FEATURES
• Line interface with:
– Voltage regulator with programmable DC voltage
drop
– Programmable set impedance
– Output to control an external switching MOS
transistor for pulse dialling
– Programmable DC voltage during pulse dialling
– Circuitry for short DC settling time
• Interface to peripheral circuits with:
– Supply for microcontroller and DTMF diallers
– Input to sense supply voltage of microcontroller and
output for reset of microcontroller
– I2C-bus (programming of parameters, control of all
logic signals)
– High impedance DTMF signal input
– Input for external oscillator signal with on-chip DC
blocking
– Power-down via the I2C-bus
– Stabilized supply for electret microphone
• Microphone and DTMF amplifiers:
– Low-noise microphone preamplifier suitable for
various types of microphones
– Symmetrical high impedance microphone
preamplifier inputs
– Programmable gain for microphone and DTMF
channels
– Sending mute via the I2C-bus to disable microphone
amplifier and enable DTMF amplifier
– Sending mute also to be used as privacy switch
– Dynamic limiting (speech controlled) to prevent
distortion of line signal and sidetone; programmable
maximum sending level
• Receiving amplifier:
– Suitable for various types of earpieces (including
piezo)
– Programmable gain and hearing protection level
– Receiving mute via the I2C-bus to disable receiving
amplifier and enable DTMF confidence tone
– On-chip anti-sidetone circuit with programmable
sidetone balance
– Confidence tone in the earpiece during DTMF dialling
• Facility to regulate parameters with line current:
– Value of DC line current (bit code) readable via the
I2C-bus
– Line loss compensation with fully software
programmable characteristics (control range, stop
current) of microphone/earpiece/DTMF amplifiers
– Fully software programmable control of sidetone
balance and DC voltage drop as a function of line
length.
APPLICATIONS
• Wired telephony (basic till feature phones)
• Combi-terminals (e.g. telephone and answering
machine or FAX)
• Modems and base units of cordless telephones.
GENERAL DESCRIPTION
The PCA1070 is a CMOS integrated circuit performing all
speech and line interface functions in fully electronic
telephone sets. The device requires a minimum of external
components. The transmission parameters are
programmable via the I2C-bus. This makes the IC
adaptable to nearly all worldwide country requirements
and to a various range of speech transducers, without
changing the (few) external components.
The parameters are stored in the EEPROM of a
microcontroller and are loaded into the PCA1070 during
the start-up phase of the transmission IC after hook-off.
The PCA1070 also allows adaptation to the connected
telephone line by reading the line current via the I2C-bus
and processing it in the microcontroller.
1997 Jun 20
2
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